Messages in this thread | | | Date | Tue, 23 Apr 2013 10:43:55 +0800 | From | Huang Shijie <> | Subject | Re: [PATCH v2 3/8] mtd: get the ECC info from the Extended Parameter Page |
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于 2013年04月23日 05:22, Brian Norris 写道: > On Mon, Apr 22, 2013 at 12:47 AM, Huang Shijie<b32955@freescale.com> wrote: >> Since the ONFI 2.1, the onfi spec adds the Extended Parameter Page >> to store the ECC info. >> >> The onfi spec tells us that if the nand chip's recommended ECC codeword >> size is not 512 bytes, then the @ecc_bits is 0xff. The host _SHOULD_ then >> read the Extended ECC information that is part of the extended parameter >> page to retrieve the ECC requirements for this device. >> >> This patch implement the reading of the Extended Parameter Page, and parses >> the sections for ECC type, and get the ECC info from the ECC section. >> >> Tested this patch with Micron MT29F64G08CBABAWP. >> >> Signed-off-by: Huang Shijie<b32955@freescale.com> >> --- >> drivers/mtd/nand/nand_base.c | 54 ++++++++++++++++++++++++++++++++++++++++++ >> 1 files changed, 54 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c >> index beff911..48ff097 100644 >> --- a/drivers/mtd/nand/nand_base.c >> +++ b/drivers/mtd/nand/nand_base.c >> @@ -2846,6 +2846,56 @@ static u16 onfi_crc16(u16 crc, u8 const *p, size_t len) >> return crc; >> } >> >> +/* Parse the Extended Parameter Page. */ >> +static void nand_flash_detect_ext_param_page(struct mtd_info *mtd, >> + struct nand_chip *chip, struct nand_onfi_params *p, int last) >> +{ > I think we want a return code (int) for this function. It obviously > can fail, and the caller needs to know this. I not sure who will uses ecc_strength/ecc_size, except the gpmi. So i ignore the return value.
If you think we should add it, i will add it. > The "last" parameter is not very obvious until you read the whole > function, where you see that this function assumes a lot about the > caller. Please address the comments below and/or fully document the > parameters and calling context for this function. > ok. I can add more comments.
>> + struct onfi_ext_param_page *ep; >> + struct onfi_ext_section *s; >> + struct onfi_ext_ecc_info *ecc; >> + uint8_t *cursor; >> + int len; >> + int i; >> + >> + len = le16_to_cpu(p->ext_param_page_length) * 16; >> + ep = kcalloc(1, max_t(int, len, sizeof(*p)), GFP_KERNEL); >> + if (!ep) >> + goto ext_out; >> + >> + /* >> + * Skip the ONFI Parameter Pages. >> + * The Change Read Columm command may does not works here. > Why not? > You can give me a fix patch which bases on my patch set. I can test it. :)
I tried to use the Change-read-columm command, but failed.
>> + */ >> + for (i = last + 1; i< p->num_of_param_pages; i++) >> + chip->read_buf(mtd, (uint8_t *)ep, sizeof(*p)); > You never sent a command to the chip. How can you expect to read from it? we have sent a command in the nand_flash_detect_onfi(). > It seems that you are writing this function with the assumption of a > particular calling context (a context in which the last command was > CMD_PARAM). IMO, it would make a lot more sense that this function > actually send its own CMD_PARAM followed by either X bytes of skipped > read_buf() or a change read column command. Then it doesn't need the > "last" argument, and its usage makes much more sense. > I added the "last" argument just because the Change-read-column command did not works.
thanks Huang Shijie
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